SkPDF: fix fTextScaleX error

BUG=skia:7315
Change-Id: Ic613cb6fb8faed5b0840db4f500940bd6823de66
Reviewed-on: https://skia-review.googlesource.com/76981
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
3 files changed